Diesel swap...

[JHG]

I have been going through lot of post after a search, but have not found what I am looking for.

I have known for some time now that my carburated 350 sbc is not going to live forever. The power is great but oil pressure has been dropping and I have to add at least 2 quarsts of oil per month.

So I have to get me another engine and I am considering a diesel swap (gas prices are horrible over here).

I use my /forums/images/graemlins/k5.gif as often as I can (daily from sept to may), and dont want to have to buy some economybox.

If I swap a diesel in I have to choose between 6.2, 6.5 or 6.5TD. 6.5TD are hard to find in Iceland, and I think they are to exspensive to import from US /forums/images/graemlins/frown.gif

I want to know from people who have made a diesel swap:

1) Are there any regrets?
2) How many miles per gallon are you getting compared to a small block?
3) How difficult/time consuming is it?

I have a TH350 right now but if I will do the swap I will swap in a TH700, because I have 4.88 and 38" tires (~3000 rpm at 60 mph with TH350).

Thanks,

Jon H.

 

[mrk5]

I've swapped from a 6.2 to a 350. I know, the opposite of what you are wanting to do. But I'll give some input based on my experience. With the 6.2, TH400, 33" tires I was getting 18-20mpg. I think that it would be alot of work to go from gas to diesel engine. The reason I switched to the 350 is because a naturally aspirated diesel is quite frankly gutless. If you go diesel, turbo charge. Try this website for more info. www.62-65-dieselpage.com I belonged while I had by 6.2 and it is a very informative site. I really think if you did the math, it would take a long time for the saving is fuel costs to pay back the expense of a diesel. Course I don't know what your gas prices are. It would would probably be better to buy a truck with a diesel already in it. They made early to mid 90's two-door Tahoes with 6.5L turbo diesels. /forums/images/graemlins/thumb.gif

 

[tRustyK5]

I did the swap from a 350 to a 6.2 diesel 18 months ago. My 81 Jimmy was getting me an average of 9 mpg (U.S. gallon or 3.78 litres)/forums/images/graemlins/1zhelp.gif

My 81 Jimmy has 4.56 gears and an SM 465 and runs on 39.5" TSL's. I now average between 15 and 16.5 mpg /forums/images/graemlins/thumb.gif, and an overdrive would increase that to 20 without any trouble. I currently spin approx 2600 on the freeway which isn't the most efficient rpm for a diesel.

My only regret was not having done this 7 years ago when I first bought my truck.

I find the 6.2 has close to the same power as my old 350, more low end grunt though. The 350 had slightly better acceleration.

The swap itself isn't that bad, I highly reccomend getting a complete donor truck though. I originally bought the 6.2 >>> "and everything you need dude" <<< /forums/images/graemlins/rolleyes.gif then quickly found out I needed a lot more than I thought. My buddy and I bought a 2WD one ton pick-up that had a 6.2 about a month later for parts. He wanted the 14 bolt rear and I wanted to get all the little things so I could finish my swap.

It does all bolt up though...that part is easy. Having a complete donor next to your truck when you're doing it is priceless though (pardon the cliche)

Overall I've been very happy with my 6.2, I've logged 20,000 km on it since I did the swap and it's been trouble free. Wheeling is a pleasure now, no stalling at wierd angles and it has enough grunt at idle to chug it's way over stuff like nothing now. A full day of wheeling doesn't end up costing me $50 for fuel either.

Not to sound pushy, but you might consider a membership here so you get access to the diesel forum. There are more than a few guys there that have done this swap (aside from me) and you'll probably get a much more comprehensive response. /forums/images/graemlins/waytogo.gif

Good luck!

Rene

 

[tRustyK5]

A 6.2 and TH400 with 3.08's and 33's should be gutless...especially at altitudes high enough to induce spontaneous nosebleeds. /forums/images/graemlins/histerical.gif

A 6.2 with 4.88's is gonna have a fair bit of snap. With 4.56's I find it's quite comparable to my old 350.

At any rate...a turbo is a good idea, especially at higher altitudes.

Rene

 

[mrk5]

Actually I have 3.73 gears, but to be fair I do think my 6.2 was tired.
That website I mentioned has some really cool rebuild ideas for 6.2 & 6.5 that get some serious horsepower without turbos. And I too would recommend the full membership to ColoradoK5, everyone here is very ready and able to help.

 

[JHG]

Currently my Blazer is getting me around 8-10 mpg. If it could get 15-20 mpg that would pay for the swap in one year /forums/images/graemlins/shocked.gif

The liter of gas costs around 1.46 USD, thats 5.52 per gallon. I spend around 4.500 USD in gas every year. /forums/images/graemlins/angryfire.gif

The dream would be 6.5TD but they are hard to find over here, and I think they are rather exspensive in the US. I will probably buy a 6.2 and TH700, and start saving money.

I know a junkyard near me bought 40 trucks from the military few months ago, perhaps I should look into that (arent military 6.2 a little more powerfull than the civil version?).

Is there a way to predict how many hours this swap could take? At the moment the /forums/images/graemlins/k5.gif is my only transportation but soon I will bring out my Transam, then I can rest the /forums/images/graemlins/k5.gif for few months.

I have been considering getting a full membership. I am a member in few local clubs, and it ads up. I have seen that CK5 is a great site /forums/images/graemlins/waytogo.gif.

Thanks,

Jon H.

 

[BlazerGuy]

The military CUCV 6.2 are the same as the civvy's...

 

[mrk5]

Actually there is a difference, but it is minor. There are two different VIN codes and one ends in J and the other C. I can't remember which is the civilian code. It has to do with emissions. I think the civilian models come with an EGR(?) crossover.

It doesn't make a difference in power.

The diesel page recommends installing single big exhaust on 6.2's without the crossover and keeping the duals on those with it.

 

[BlazerGuy]

Ah, sol. I was under the impression that the civilian models came with the J code also... /forums/images/graemlins/doah.gif

 

[tRustyK5]

The 'C' code with the EGR was the light duty version and only found in the half ton's. The 3/4 tons and one tons got the 'J' code which has no EGR and makes more power. I have a 'J' code in my Jimmy. I'd guess the military versions got the 'J' codes.

They are easy to identify, once you pull off the air cleaner on a 'J' code it should look like a huge 4 barrel manifold without a carb...the 'C' code is similar but has an EGR contraption there.

Here is a pic of my 'J' code (no injector pump in the pic)

Rene

 

[Diesel Dan]

That is an early model "J" intake. The later ones are a single plenum, or open design verses the pictured dual plane.

 

[AgDieseler]

The CUCV engines as well as the 82 & 83 engines have a higher Ni content in the block. That gives better resistance to ring wear, better vibration qualities, and make it a little bit heavier. CUCV 6.2Ls are a good choice when building an engine.

 

[JHG]

Does anybody know where I can find hp and torgue numbers for 6.5? In Project Blazer I found those numbers for 6.2:

6.2 N/A, 94 hp, 272lb-ft
6.2 w/Banks Turbo 172 hp, 451 lb-ft

But how much is hp and torgue is 6.5 and 6.5TD making in stock form?

Thanks,

Jon H.

 

[tRustyK5]

You have to look for the 'new baseline' numbers...those represent a healthy but not new 6.2. 114 hp and 329 lbs of torque with a 'C' code intake and crapy exhaust. With a 'J' code intake and good exhaust it made 134 hp and 359 lbs of torque to the rear wheels. Not bad numbers for a N/A diesel.

Rene